Page 135 - Start Up Mathematics_5

(b) In how many hours will they reach Delhi from Kalka if they travel by train
number 12006?

(c) Which train takes more time from Kalka to Delhi?
(d) If they travel by train number 12011, how much time will it take to go
from Chandigarh to Kurukshetra?

Solution: (a) Time of departure from Kalka = 6:15 p.m.
Time of arrival at Ambala = 7:38 p.m.

Number of hours = 7:38 p.m. – 6:15 p.m. = 7 h 38 min – 6 h 15 min
= 1 h 23 min

(b) They will reach Delhi in 4 hours. (10:15 p.m. – 6:15 p.m.)
(c) Train number 12011 takes 4 h 10 min and train number 12006 takes 4 h.
So, train number 12011 takes more time.
(d) Time of departure from Chandigarh = 18:23 p.m.

Time of arrival at Kurukshetra = 20:28 p.m.
Number of hours = 20:28 p.m. – 18:23 p.m. = 20 h 28 min – 18 h 23 min
= 2 h 05 min

Word Problems

Example 9: Shreya studies for 5 hours everyday. How many hours does she study in a
fortnight? (Hint: 1 fortnight = 15 days)

Solution: Number of hours Shreya studies in 1 day = 5 hours
Number of hours Shreya studies in 15 days = 5 × 15 hours = 75 hours

So, Shreya studies for 75 hours in a fortnight.

Example 10: An Indian Airlines flight leaves Mumbai at 7:15 a.m. The flight takes 2 h 20
min to reach Goa. At what time will it reach there?

Solution: Time of departure from Mumbai = 7:15 a.m., i.e., 7 h 15 min
Time taken by the flight = 2 h 20 min
Time of arrival at Goa = 7 h 15 min + 2 h 20 min = 9 h 35 min

So, the flight will reach Goa at 9:35 a.m.

EXERCISE 9.2

1. Aditya plays for 1 h 30 min in the morning and 45 min in the evening. For how many
hours does Aditya play in a day?
2. Rashi attends school from 8:00 a.m. to 12:30 p.m. For how many hours does Rashi
attend the school?

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